摩擦式出钢机的优缺点是什么?
参考答案:
摩擦式出钢机的缺点是推力小,它的优点是当推动钢料过程中,若钢料被卡住,送进辊与推杆之间就会打滑,推杆就停止前进,对设备起到保护作用。
He said _____. [ ]
A. that I am a teacher
B.I was a teacher
C. that he is a teacher
D. he was a teacher
已知A、B均为集合U={2,4,6,8,10}的子集,且A∩B={4},(CUB)∩A={10},则A=______.